CN103618394A - A disc motor stator with heat pipe winding - Google Patents

Abstract

A disc motor stator using heat pipe windings, characterized in that the disc motor stator uses heat pipe windings, and the heat pipe windings are arranged and connected to form a stator winding disc. Each heat pipe winding is composed of multiple coils connected in series or in parallel. Each coil (2) is composed of one or more heat pipes (3); the heat pipes (3) forming the same coil are connected together through the ends of the heat pipes. The heat pipe (3) is a hollow pipe with both ends closed, and the inside of the heat pipe (3) is filled with non-conductive cooling liquid. The outer surface of the heat pipe (3) is insulated.

Description

A disc motor stator with heat pipe winding

technical field

The invention relates to a stator structure of a disc motor, in particular to a structure suitable for a heat pipe winding of a permanent disc motor.

Background technique

The permanent disk motor is mainly composed of a stator and a rotor, and the shape of the motor is a flat disk. The stator and the rotor are also disk-shaped structures, which are called stator disk and rotor disk here. Usually, the stator disk is a winding disk, and the rotor disk is a magnetic steel disk. The stator winding disc is generally made of multi-turn coils or flat copper wires. The rotor magnetic steel disc is generally composed of multiple magnetic steels arranged in sequence according to the magnetization direction. The stator disc and the rotor disc are perpendicular to the motor shaft. to install.

The structure of the existing disk motor stator winding disk is generally shown in Figure 1. Taking an 8-pole 12-slot motor as an example, a stator winding disk is formed by arranging a plurality of coils as shown in Figure 2 in a certain way. Each coil can be made of flat copper wire, or wire wound in a certain way, or made by other existing coil manufacturing methods. The existing arrangements of the coils forming the entire stator winding disk are applicable here. The rotor magnetic steel disk is shown in Figure 12.

The disc motor is an ideal driving device due to its small size, light weight and high power density. In recent years, with the development of disc motors and the continuous expansion of application fields, the performance requirements are getting higher and higher. The temperature rise of the motor is an important indicator of the performance of the motor, and under the same working conditions, the temperature rise of the motor depends on the heat dissipation capacity of the motor.

The main heat-generating part of the disc motor is the stator, which is usually cooled by natural air or water cooling with water channels in the motor casing to dissipate heat from the stator of the disc motor. The natural air-cooled heat dissipation method is not enough to remove enough heat when the motor is running at high power, which will easily cause the motor to overheat and shorten the time of high-power operation and the life of the motor. Since the stator winding disk of the disk motor is placed perpendicular to the axial direction, only the winding end on the outer side of the stator disk is close to the motor casing. Therefore, water cooling and heat dissipation of the motor by arranging water channels in the motor casing is not enough to dissipate the heat of the winding. Spread out, less effective. In addition, in the stator plate structure casted with epoxy resin, in the prior art, there is a method of adding heat-conducting insulating powder such as aluminum nitride to the epoxy resin to improve the thermal conductivity of the epoxy resin, but this method is always On the one hand, the manufacturing process is relatively complicated, and on the other hand, it is still not enough to dissipate the heat generated by the stator winding when the high-power disc motor is running.

The heat pipe is mainly composed of three parts: the shell, the liquid-absorbing core and the end cover. After the inside of the heat pipe is pumped into a negative pressure, an appropriate amount of liquid is filled. There is a liquid-absorbing core structure on the inner wall of the heat pipe. After the capillary porous material of the liquid-absorbing core is filled with liquid, the heat pipe is sealed. The heat pipe is divided into an evaporating section and a condensing section along the axial direction. When the evaporating section of the heat pipe is heated, the liquid in the liquid-absorbing core is heated and vaporized. It flows to the condensation section, where the steam condenses into a liquid when it meets condensation, and releases heat. Then, the condensed liquid flows back to the evaporation section under the action of capillary force generated by the liquid-absorbing wick, and continues to absorb heat and vaporize. This process is the heat dissipation of the heat pipe. a cycle. The heat pipe realizes heat transfer by the phase change of the internal working liquid, and the cooling liquid is refluxed by capillary action to complete a cycle. In such a continuous cycle, the heat is transferred from the hot end of the heat pipe to the cold end, that is, from the evaporating section to the condensing section. This process continues in cycles as long as the heat source is available. Heat pipes have many advantages such as high thermal conductivity, excellent isothermal properties, variability of heat flux density, reversibility of heat flow direction, environmental adaptability, etc., and are simple in structure, reliable in operation, and good in temperature uniformity. In recent years, heat pipe technology has been increasingly used in various fields.

In the prior art, heat pipes are used in the motor to dissipate heat. The stator winding adopts the current commonly used stator winding materials and forms, and only a certain space is reserved for the heat pipe in the winding arrangement, and the heat pipe is only used for heat transfer and heat dissipation. On the one hand, due to the uneven arrangement of the heat pipes in this configuration, the heat dissipation effect is not optimal, and it is easy to cause uneven temperature distribution of the stator winding. On the other hand, in order to place the heat pipe in the proper position of the winding, it is also necessary to consider the fixing method of the heat pipe, which increases the complexity of the motor structure. Whether the heat pipe placed in the winding will affect the electromagnetic and mechanical properties of the motor also needs further discussion .

In the prior art, the heat pipe is made into a U shape, and the arms at both ends of the U shape heat pipe are not equal in length. The U-shaped heat pipe is fixed between the motor casing and the stator winding, and a water channel is arranged in the casing, and cooling water circulates in the water channel when the motor is working. The longer section of the U-shaped heat pipe is close to the stator winding as the evaporation section, and the shorter section is close to the casing as the condensation section. When the motor is working, the heat generated by the stator winding is transferred from the evaporation section of the heat pipe to the condensation section, and then the heat is taken away by the cooling water in the water channel close to the condensation section to achieve the purpose of cooling the stator winding. This existing technology only adds a heat transfer structure of a heat pipe on the basis of the traditional motor structure, and there is no substantial change in the structure of the stator winding of the motor. This method increases the outer diameter of the motor and makes the volume of the motor somewhat smaller. It is also not suitable for the heat dissipation of the stator winding of the disc motor.

There is also a prior art that provides a cooling device for the windings of a permanent magnet motor, which includes a plurality of heat pipes arranged in the stator slots and intersecting with the windings, each heat pipe is in close contact with the windings, and each heat pipe extends out of the windings The ends of the coils are in contact with the air outside the winding ends. This technology has a simple structure and is easy to implement, but it cannot guarantee the uniformity and high efficiency of stator winding heat dissipation, and it is not practical for disc motors.

In the above prior art, there is no breakthrough in the traditional stator winding structure, and they are all proposed on the basis of the structure of the radial flux motor, which is not suitable for the special structure of the disc motor.

Contents of the invention

The purpose of the present invention is to solve the problem of insufficient heat dissipation of the stator winding of a disk motor, and to propose a stator of a disk motor with heat pipes as windings by utilizing the excellent heat transfer and heat dissipation performance of the heat pipe and the electrical conductivity of the metal shell. The invention can overcome the shortcomings of insufficient heat dissipation capacity of motor stator windings in the prior art and poor applicability of the prior art to disc motors.

The feature of the present invention is to make full use of the heat transfer and heat dissipation capabilities of the heat pipe and the good electrical conductivity of the copper shell. According to the needs of the stator winding, the heat pipe is properly deformed to construct the stator winding of the disc motor. The heat pipe winding has self-dissipating ability while ensuring the performance of the motor. In addition, the present invention designs the shape of the heat pipe according to the special structure of the disc motor and its requirement for the coil structure constituting the stator winding, which breaks through the winding form of the existing disc motor. From the perspective of the stator winding structure of the disc motor, it simplifies the structure of disposing heat dissipation devices in the winding formed by flat copper wires or other forms of wires due to heat dissipation. From the perspective of the heat dissipation of the stator winding of the disc motor, the self-dissipation capacity of the heat pipe winding, coupled with the auxiliary air cooling or water cooling, greatly improves the heat dissipation capacity of the stator winding of the disc motor.

The invention adopts heat pipes to replace the traditional disk-type motor stator windings, adopts a plurality of heat pipes arranged in a certain way and connected together to form the stator windings of the disk-type motor, and then makes the stator winding disks through a certain process. The disc motor with the stator winding composed of heat pipes uses the phase change of the working liquid in the heat pipe and the capillary action of the liquid-absorbing core to perform heat exchange, effectively transferring heat from the evaporation section of the heat pipe to the condensation section, and realizing the self-radiation of the stator winding. While the heat pipe itself dissipates heat, it can assist other heat dissipation methods to further enhance the heat dissipation capacity of the motor. In particular, it is necessary to dissipate heat at the end of the winding as the condensation section to improve the heat exchange capacity of the heat pipe, and at the same time transfer the heat to the condensation section effectively. spread out. For example, fan blades are added to the inner wall of the motor end casing to enhance the flow of air, enhance the heat dissipation effect of natural air cooling, and take away part of the heat generated by the winding. It is also possible to set a water channel in the motor casing, and use water cooling to dissipate the heat generated by the stator winding through the circulation of cooling water, especially to effectively cool the end of the stator winding that is close to the inner wall of the motor casing as the condensation section. . In order to achieve a better heat dissipation effect, a combination of various cooling methods can be used.

While the external cooling dissipates heat from the motor, the winding composed of heat pipes can realize self-dissipation, achieving a double heat dissipation effect.

The technical scheme adopted in the present invention is:

The invention discloses a disc motor stator adopting heat pipe windings. The heat pipe windings are arranged and connected in a certain way to form a stator winding disc. The heat pipe winding of each phase is composed of a plurality of coils connected in series or in parallel, and the present invention is applicable to the arrangement of the coils forming the stator winding disc of the disc motor. Each coil consists of one or more heat pipes. The heat pipes that form the same coil are connected together through the ends of the heat pipes, and flat copper wires or other forms of wires can be used for connection. When the stator winding disk is composed of heat pipes, according to the structure of the disk motor and the size of the stator disk, the heat pipes constituting the stator winding are made into a U-shape, and multiple U-shaped heat pipes are nested and arranged and connected by wires through the ends of the heat pipes to form a coil , multiple coils are arranged to form the entire stator winding disk. As the main component of a coil, the outer surface of each heat pipe needs to be insulated according to the insulation level of the motor.

The U-shaped heat pipe is divided into three sections, namely the left and right sections near the end of the heat pipe and the middle section located in the middle of the heat pipe. The left and right sections near the end of the heat pipe are placed radially along the motor, and the middle section is tangentially along the outside of the motor stator. place. The heat pipe is a hollow pipe with both ends closed, and the inside of the heat pipe is filled with non-conductive cooling liquid. When the motor is working, the metal part of the heat pipe wall has an electric current passing through, and the heat pipe winding generates heat. Since the heat pipe windings at the radial position of the stator winding disk are relatively dense, the heat dissipation effect of the two heat pipes located at the radial position of the motor is not as good as that of the middle heat pipe. Therefore, during the working process, the left and right sections placed radially along the motor near the end of the heat pipe have a higher temperature and serve as the evaporation section, and the middle section placed tangentially along the outer side of the motor stator has a lower temperature and serve as a condensation section. When the evaporating section of the heat pipe is heated, the liquid in the liquid-absorbing wick on the inner wall of the heat pipe is heated and vaporized, and the vaporized steam flows to the condensing section under the action of a small pressure difference. In the condensation section, the steam condenses into liquid and releases heat. Then, the condensed liquid flows back to the evaporation section under the action of the capillary force generated by the liquid-absorbing core, and continues to absorb heat and vaporize, which is a cycle of self-radiation of the heat pipe winding of the disc motor. If the cycle continues in this way, the heat generated by the heat pipe windings during the operation of the motor will be consumed through the phase change of the working fluid inside the heat pipe to achieve the purpose of heat dissipation. While the heat pipe itself dissipates heat, the auxiliary cooling method of air cooling or water cooling is used to further enhance the heat dissipation capacity of the motor, especially the water cooling method of setting water channels in the motor casing to effectively dissipate heat at the end of the winding close to the inner wall of the motor casing as the condensation section, Therefore, the heat exchange capacity of the heat pipe is improved, and the heat exchanged to the condensation section of the heat pipe is effectively dissipated. The entire stator winding disk can be made by any current stator disk manufacturing process suitable for disk motors, such as encapsulating the coils in an insulating material containing polyester fiber plastic or phenolic plastic, and pressing it into the entire stator winding disk.

Further, in order to save space and facilitate winding arrangement, the left and right sections of each U-shaped heat pipe located in the radial direction near the end of the heat pipe, that is, the evaporation section of the heat pipe is made flat, and the section of the flat heat pipe The flat plane is perpendicular or at an angle to the plane where the heat pipe is located. The plane where the heat pipe is located is a plane perpendicular to the motor axis. The condensation section located in the middle of the heat pipe in the tangential direction outside the stator remains unchanged. In this way, on the one hand, the flat heat pipe is easy to place, on the other hand, it can save space, and the length of the air gap can be adjusted according to the angle between the flat heat pipe at both ends and the axial direction of the motor, so as to optimize the electromagnetic performance.

Furthermore, when a coil is composed of multiple heat pipes, the ends of adjacent heat pipes are connected in turn to form a coil. For this reason, the ends of the heat pipes are made into flat joints, and the inner and outer phases are connected by flat copper wires or other forms of wires. Adjacent heat pipes can be connected by any suitable means such as welding.

Furthermore, the coils also need to be connected together with flat copper wires or other forms of wires, and are connected in series or in parallel according to the configuration of the motor windings to form a certain phase winding of the disc motor stator. The entire stator winding disk of the disk motor is then composed of multi-phase windings.

In addition to using heat pipes as stator windings in the present invention, other motor parts and processes can be any form suitable for disc motors. For example, the rotor magnetic steel disk of the present invention can be any form suitable for the rotor of a disk motor.

The beneficial effects of the present invention are: a disc motor stator using heat pipe windings in the present invention, the stator winding of the disc motor is constructed with heat pipes, which solves the heat dissipation problem of the disc motor stator and improves the performance of the disc motor .

Description of drawings

Fig. 1 is a schematic diagram of a disc motor stator winding disc in the prior art;

Fig. 2 is a schematic diagram of the coils forming the stator winding discs of the disc motor in the prior art;

Fig. 3 is a schematic diagram of a disk motor stator winding disk according to an embodiment of the present invention;

Figure 4 is a schematic diagram of the connection of each group of coils of the A-phase winding of the stator of the disc motor;

Fig. 5 is a schematic diagram of arrangement of heat pipes forming a group of coils;

Fig. 6 is a schematic diagram of connecting multiple heat pipes forming a group of coils;

Figure 7a is a schematic plan view of the evaporation section and condensation section of a single heat pipe constituting the winding, and Figure 7b is a schematic plan view of the heat pipe and the liquid-absorbing wick;

Fig. 8 is a three-dimensional view of a single U-shaped heat pipe forming a stator winding according to an embodiment of the present invention;

Figure 9 is a three-dimensional view of a single U-shaped heat pipe made flat at both ends;

Fig. 10a is a schematic cross-sectional view of a circular section of a heat pipe forming a winding, and Fig. 10b is a schematic cross-sectional view of a flat section of a heat pipe forming a winding;

Fig. 11 is a schematic diagram of the ends of the heat pipes forming the stator winding according to the embodiment of the present invention;

Figure 12 Schematic diagram of the rotor magnetic steel disk;

Among the figures: 1. The coils forming the stator winding disc in the prior art disc motor, 2. Coils, 3. Heat pipes, 4. Lead wires, 5. Heat pipe end joints, 6. Tube shells, 7. Inner walls, 8. Liquid-absorbing cores, 9. End caps, 10. Evaporation section, 11 condensation section, 12 permanent magnet, 13 rotor magnetic steel disk.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 3, in the embodiment of the present invention, heat pipes 3 are used to form a disk-type motor stator with windings, and the multi-phase heat pipe windings are connected in a certain way to form a stator winding disk. 4. The heat pipe winding of each phase is composed of a plurality of coils 2 connected in series or in parallel, and the currently available arrangements of the coils forming the stator winding disc of a disc motor are applicable here. Each coil 2 is composed of one or several heat pipes 3 , as shown in FIG. 5 , in this embodiment, one coil 2 is composed of three heat pipes 3 , and the heat pipes 3 are made into a U shape, nested inside and outside. The size and shape of the heat pipe 3 are selected according to the size of the stator plate and the number of stator slots. The heat pipes 3 constituting the same coil 2 are connected together through heat pipe end joints 5 , and flat copper wires or other types of wires 4 can be selected for connection. In this embodiment, the connection of three-phase windings is used for illustration. In Figure 3, A, B, and C indicate the positive extreme lines of each phase of the three-phase winding, and X, Y, and Z indicate the negative extreme lines corresponding to each phase. Terminals A, B, and C are drawn out as three-phase lines, and terminals X, Y, and Z are usually connected in star or delta connection.

When the stator winding of the disk motor is composed of heat pipes 3, according to the structure of the disk motor and the size of the stator disk, the heat pipes 3 forming the stator winding are made into a U shape, and the outer surface of each heat pipe is made correspondingly according to the insulation level of the motor. Insulation treatment. The U-shaped heat pipe 3 forming the stator winding is divided into three sections during operation, namely two sections near the ends of the heat pipe and a middle section located in the middle of the heat pipe. The two sections near the end of the heat pipe are placed radially along the motor, and the middle section is placed tangentially along the outside of the motor stator. The heat pipe 3 is a hollow pipe with both ends closed, and the inside of the heat pipe is filled with non-conductive coolant. When the motor is working, the metal part of the heat pipe wall, that is, the shell 6, has an electric current to pass through, and the heat pipe winding generates heat. The heat pipe windings in the radial position of the stator winding disk are relatively dense, so that the two heat pipes located in the radial position of the motor do not have as large a contact area with the outside as the middle section, and the heat dissipation effect of the two heat pipes near the end is slightly worse than that of the middle section. Therefore, during the working process of the motor, the temperature of the two sections of the heat pipe near the end placed along the radial direction of the motor is higher, as the evaporation section 10, and the temperature of the middle section of the heat pipe tangentially placed outside the motor stator is lower, as the condensation section 11, as shown in Figure 7a and Figure 7b. When the evaporating section 9 of the heat pipe 3 is heated, the liquid in the liquid-absorbing wick 8 on the inner wall 7 of the heat pipe 3 is heated and vaporized, and the vaporized steam flows to the condensing section 11 under the action of a small pressure difference, and in the condensing section 11 When the steam meets condensation, it condenses into liquid and releases heat. Then, the condensed liquid flows back to the evaporation section 10 under the capillary force generated by the liquid-absorbing core 8, and continues to absorb heat and vaporize, which is a cycle of self-radiation of the heat pipe winding of the disc motor. If this cycle continues, the heat generated by the heat pipe windings during the operation of the motor will be consumed through the phase change of the working liquid inside the heat pipe 3, so as to achieve the purpose of heat dissipation. While the heat pipe 3 itself dissipates heat, the auxiliary cooling method of air cooling or water cooling is used to further enhance the heat dissipation capacity of the motor, especially the water cooling method of setting water channels in the motor casing to effectively dissipate heat at the end of the winding close to the inner wall of the motor casing as the condensation section , so as to improve the heat exchange capacity of the heat pipe and effectively dissipate the heat exchanged to the condensation section.

Further, in the embodiment shown in FIG. 3, each U-shaped heat pipe 3 shown in FIG. The surface and the plane where the heat pipe is located, that is, the plane perpendicular to the axial direction of the motor, are perpendicular or at a certain angle, and the condensation section 11 of the heat pipe 3 located on the outside of the stator in the tangential direction remains unchanged. In this way, on the one hand, the flat heat pipes at both ends are easy to place, and on the other hand, they also save space for the stator winding disk. The length of the air gap can also be adjusted according to the angle between the flat heat pipes at both ends and the axial direction of the motor, so as to optimize the electromagnetic performance.

The cross-section of the U-shaped heat pipe whose two ends are made flat as shown in Figure 9 is shown in Figure 10, and Figure 10a shows the cross-section of the circular section of the heat pipe 3 shown in Figure 9, which acts as a condensate during the heat pipe 3 working process Section 11, FIG. 10b shows the cross-section of the flat section of the heat pipe 3 shown in FIG. When the motor is working, current flows through the metal tube shell 6, and the liquid-absorbing core 8 on the inner wall 7 of the heat pipe 3 is filled with liquid, which is heated and vaporized in the evaporation section 10, and the liquid condensed in the condensation section 11 passes through the capillary of the liquid-absorbing core 8 The working stream returns to the evaporation section 10 to continue absorbing heat.

Further, as shown in FIG. 6, when a coil 2 is composed of a plurality of heat pipes 3, the ends of adjacent heat pipes 3 should be connected in turn to form a coil 2. For this reason, the ends of the heat pipes are made as shown in FIG. 11 The flat joints here are referred to as heat pipe end joints 5, and the inner and outer adjacent heat pipes 3 are connected together with flat copper wires or other forms of wires 4, and any suitable method such as welding can be used for the connection.

Figure 8 is a three-dimensional schematic diagram of the circular heat pipe 3 before it is made into a flat shape. Joints 5 are made at both ends of the heat pipe. wire connection.

Further, after the single coil connection is completed, the coils also need to be connected with flat copper wires or other forms of wires 4. According to the winding configuration form of the motor, a certain phase winding of the stator of the disc motor is selected in series or in parallel, as shown in Fig. 4 is a schematic diagram of a phase A winding composed of four coils connected in series in this embodiment. The entire stator winding disk of the disk motor is composed of multi-phase windings. Figure 3 shows the stator winding of the disk motor composed of three-phase windings.

In addition to using the heat pipe 3 as the stator winding in the present invention, other motor parts and processes can be any form suitable for the disc motor. For example, the rotor magnetic steel disk 13 can be any form suitable for the rotor of a disk motor. The structure of the rotor magnetic steel disk in this embodiment is shown in FIG. 12 . In this embodiment, the rotor magnetic steel disk 13 adopts a structure of 8 magnetic poles, and the S pole permanent magnets 12 and the N pole permanent magnets 12 are arranged alternately. The design of the rotor magnetic steel disk 13 can adopt any current design method for the magnetic steel disk of a disk motor.

The disc motor using the heat pipe 3 to form the stator winding of the disc motor is beneficial to the heat dissipation of the motor, and is especially suitable for a disc motor with a high calorific value that requires high-power operation.

Claims (4)

1. A disc motor stator adopting heat pipe windings, characterized in that, the disc motor stator adopts heat pipe windings, and the heat pipe windings are arranged and connected to form a stator winding disc; each phase heat pipe winding is composed of a plurality of coils Composed in series or in parallel; each coil (2) is composed of one or more heat pipes (3); the heat pipes (3) forming the same coil are connected together through the ends of the heat pipes; the heat pipes (3) are hollow with closed ends The pipe, the inside of the heat pipe (3) is filled with non-conductive cooling liquid; the outer surface of the heat pipe (3) is insulated. 2. The stator of the disc motor according to claim 1, characterized in that, the heat pipe (3) is U-shaped; the left and right sections of the U-shaped heat pipe (3) near the end of the heat pipe are placed radially along the motor , as the evaporation section, the middle section of the U-shaped heat pipe (3) located in the middle of the heat pipe is placed tangentially along the outside of the motor stator, as the condensation section. 3. The stator of a disc motor according to claim 2, characterized in that, the evaporation section (10) of the heat pipe (3) located in the radial direction is flat, and the flat surface of the flat heat pipe It is made to be perpendicular to or at a certain angle to the plane where the heat pipe (3) is located, and the plane where the heat pipe (3) is located is a plane perpendicular to the axial direction of the motor. 4. The stator of a disc motor according to claim 2 or 3, characterized in that, the heat pipe end joint (5) of the heat pipe (3) is flat.

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